*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html,body{
    height: 100%;
    background-image: url("../images/bg.jpg");
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover;
    background-attachment: fixed;
}



.container{
    width: 70%;
    /*减号两边必须要有空格*/
    height: calc(100% - 50px);
    /*版心居中*/
    margin: 0 auto;
    border-radius: 10px;
    /*防止溢出 滚动条效果*/
    overflow: auto;
}

.container img{
    width: 100%;
    height: calc(80%);
    margin-top: 5%;
    opacity: 0.9;
}